


Lessons

by Tigressa101



Series: Rare Pairings [7]
Category: Transformers (Bay Movies)
Genre: Age Difference, Alien Sex, Fluff and Angst, Interspecies Relationship(s), Interspecies Sex, Mech/Human, Multi, Robot/Human Relationships, Sexual Frustration, Sexual Tension, Size Difference, Size Kink, Sticky Sexual Interfacing, Xenophilia
Language: English
Status: In-Progress
Published: 2017-08-06
Updated: 2017-08-06
Packaged: 2018-12-11 23:49:24
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 2
Words: 3,779
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/11725134
Author URL: https://archiveofourown.org/users/Tigressa101/pseuds/Tigressa101
Summary: Sentinel dealt with a lot of stuff in his days. His time among the Autobots of Earth seem to be not so different after all...with a few positives.





	1. Discipline

Sentinel chuckled to himself as he watched the Twins fight once more over the Galloway’s intern. She had been among Transformers for less than a month and the Twins were already madly in love with her. Both he and Optimus found this particular quarrel funny though the young Prime hid it from the team.

His laugh silenced and a frown took over when he felt a rough push against his servo dangling by his side. It was no surprise who did it, and in return, he blindly swept his right pede to the side before an “oomph” emitted from his target. A new, sly smile formed on his faceplates. “So sorry, my dear, I thought you were one of Soundwave’s pests. Oh wait; despite not being Soundwave’s, you are a pest.”

“Interesting, the only thing I seemed to bump into just now was a walking, talking pile of trash who needs to be taken out of this establishment before he stinks up the whole place,” Arcee retorted. “Personally, I would take care of it myself, but I don’t want to be on bad terms with Optimus.”

The Prime growled as Arcee promptly shunned him with her posture crudely straight and walked away, swaying her hips as she did so. He was tired of the brat showing him off and disrespecting him in a manner too cold for even Megatron himself. Week after week, their hatred grew and each time they were forced to make eye contact, Sentinel wanted to just shoot her there and then. Of course, Optimus wouldn’t like that one bit, especially since she’s the leader of the Triplets who also have a behavior problem though not as big as hers. 

The only way to win was to make the other submit which both had no idea on how they would do that. One would have to admit the other was their superior and there was no way he was going to let a small, clever, arrogant femme get the better of him, not as long as he was still up and running.

Scowling, he let a low roar escape to express his anger, catching the attention of the Twins and Optimus. 

“Sentinel, are you okay?” The young Prime asked. He placed a servo on his mentor’s shoulder; the latter shook it off in agitation. 

“That little bitch needs to learn some respect! She’ll be the death of me if I don’t do anything about it!”

Optimus frowned, “I’ll talk to her and persuade her to leave you alone.”

“No, my student, this type of disobedience requires something more domineering. Something that will forever show her who is master! Chromia and Flare-up don’t have this problem, but Chromia already has someone to keep her in line and the purple femme follows Bumblebee around like a pet dog. Arcee is a loose rail blaster and I’m going to tame her once and for all!”

The semi vented at the implication of such a thing, but he knew Sentinel was not to be argued with, especially when he was in this sort of mood. He sighed, “Very well then, Sentinel, if that is what you desire to do as a suitable lesson. Please take care of her; she’s one of the only femmes left that we cannot afford to lose.” 

Sentinel muttered as he walked away from Optimus, “Let the lesson begin.”  
\-------------------------------------------------------------------

“Arcee,” Ironhide frowned, “You are needed in Chamber 52A. Somebody apparently requires your assistance in a matter he or she can’t do alone.”

Arcee scowled at this but didn’t retort. Instead, she obeyed and transformed into her car form. Racing to Chamber 52A made her uneasy, for her mind was telling her to just let whomever needed her help down and go enjoy the free time she had by herself. Unfortunately, doing that would alert Optimus quickly and she’d get yelled out for ditching something that could have been important. Being scolded by Optimus was worse than murdering a bunch of humans and being given the worst torture possible as punishment. It was that bad, but nobody had ever seen him do that (thank Primus).

As she approached the large warehouse, she instantly took note of the damage done to the 52A painted sign above the closed bay doors. Judging by the marking density and the metal remains that had fallen off still polished and neat meant it was done quite recently. When Arcee changed back to her robot mode, she checked the background for any mechs or femmes nearby and suspiciously, there were none.

Hesitantly, she slid the doors open and saw several blue lights active on the walls and ceiling, not too bright but not too dark either. Wires hung from remains of what looked like a former medical center or a Cybertronian control panel.

Suddenly, the doors behind her slammed shut and locked before two blue optics stared at her, its form leaning against the lining of the room. “So glad you could make it, Arcee. I was wondering when I could start.”

“Let me out, you old bastard!” She growled.

“Strong, feisty words for a small, virgin femme. I’m going to say…no.”

Arcee’s processor paused for a moment trying to catch the meaning of that sentence. “Virgin? Who told you that?”

Sentinel grinned, “I know more than you think, and I believe that is the reason you are so high and mighty. No one has claimed you so you have no reason to obey anybody unless you desire to. Well, I’m about to change that, my dear, starting right now! Lesson One: Discipline.”

He lunged at her, snarling when she darted away from his reach. “Don’t be difficult now! The sooner you submit, the better it’ll be for you!” 

Arcee scaled the beams on the walls before resting upon one that resided near a catwalk. “Get away from me!” She yelped when his servo caught her pede as she was about to jump to the beams above her. He pulled her off the masts quickly before she could squirm out of his grasp and pinned her arms to the floor after shoving her down.

The Prime ignored the pain of her servos ripping at armor and wires on his forearms as he watched her struggle. After a few minutes, she stopped but still kept her hands latched onto his arms. 

“Are you done yet?”

Arcee growled, “Bite me, you son of a bitch!”

The Rosenbauer Panther smirked, “Don’t tempt me, little femme.”

He sat on his legs as he lowered himself to hover above her chassis. Her scent was the first thing he took into thought; a strong, dark mix of emotions layered with a touch of arousal. Any mech would be head over heels after sensing that. Thankfully, he had a bit more restraint than most. Her arousal was deep but still prominent, though it didn’t have the normal characteristics of a blissful emotion. Then a new concept came to mind as her negative emotions died down and the unusual scent grew too potent quickly.

“You’re in heat, my dear? No wonder you’ve been so hard to deal with, especially these past few days. Your emotions are stressfully out of whack and I thought that it was just the typical you. I see now I was wrong,” he lustfully hissed.

Fear suddenly flared within her, which didn’t go unnoticed by the Prime. His grin grew tenfold when he scraped his digits against her waist and earned a moan in response. 

“Who do you belong to?”

“Nobody!” She grinded her denta together intimidatingly at him, hoping he would take a hint and back off. He didn’t.

He had to admit, she had the ferocity of a Fox-winged Raptor and femmes like her were fun to play with like this. The fighting spirit gave him a challenge, and he loved seeing mighty femmes fall under his control. The power, fury, and beauty of this one made his interface want to auto retract very badly. To see her beneath him, crying out his name made him hot and bothered; he loved being dominant in all interfacing sessions and this femme will submit, willingly or by force.

Sentinel picked her up off the ground before sitting against the nearest wall and compelling her to straddle his lap facing his chest. When she began pushing him away, he retaliated by grabbing her chin and roughly kissing her lip plates. 

The taste was that of sweet Energon, and he wanted more. 

His servo jaggedly tore open her interface and embedded two fingers within her. He purred as she tried to resist the pleasure he was offering her. The feistier, the better. Though he wanted to continue, he remembered the sole reason he was doing this to her. 

“I almost forgot something. Pain before pleasure; how stupid of me. Discipline needs to be taught through punishment,” he smirked.

Arcee whimpered when she was forced down onto her knee and servos, aft high and panting with the older mech’s hand keeping her down. He had a clear view of her valve and couldn’t help but stare. No, he had a job to do; he couldn’t get carried away just yet. Sentinel raised his hand and swiftly hit her aft with it, audio receptors receiving a mixed cry of grief and desire from the recipient. 

Again and again, he did this, observing how her body reacted to the punishment, how she arched to his touch when his servo hit down. “Who do you belong to?” Sentinel cooed as he eagerly continued his assault on the femme. He saw tears leaking from her optics before he heard her response that made him hum in satisfaction. “You,” she moaned in defeat.

He paused his hand in mid-air, “I’m sorry, I didn’t quite catch that. Who do you belong to?”

“I belong to you, Sentinel!” Arcee wheezed, still woozy from the spanking.

“That’s a good girl. Now, was that so hard? I could have saved you all this and just left you alone…”

Arcee cut him off, “No! I want…this. I want you, master.”

The Prime felt his interface hurt from the pressure. She had just called him “master”! The way it rolled off her tongue like that sounded magnificent. No wonder Megatron loved being called it so much. It made him feel like a king, a God even. 

He released her from the ground and lay back against the wall once more. Surprisingly, Arcee followed, sitting on his thigh plating before rubbing her wet opening on it. When she heard the clicking sound of his interface, she immediately peered up at him in need. Apparently, she was too aroused now that her heat cycle had gotten the better of her. Whether she was truly loyal to him or it was just because of the cycle itself, he didn’t know but he did know she knew she could escape him no longer. When everything did go back to normal for her, she’d still have to show him respect, for he practically owned the femme now.

“Come, Arcee, let’s see how well you obey commands. Lesson Two: Obedience.”  
\---------------------------------------------------------------------

_A week later…_

Arcee and Sentinel no longer fought one another. To the other bots’ surprise, when he called for her, she came with no hesitations. She did small errands for him and occasionally sweet talked him into doing things for her. The change was astounding and quite scary nevertheless.

Optimus gawked at the sight before turning to Sentinel and pointing at Arcee. “What else did you do to persuade her to stay with you?”

“That, my pupil, was easy. After she exited her heat cycle, I made a deal with her that if we can end this pathetic feud once and for all, I’ll be willing to help her whenever she needs it. Of course, I do require some sort of payment every now and then, but I will also teach her how to behave whenever she gets out of hand. Lately, she’s been doing that on purpose so the lessons I want to teach her don’t really…stick as much as I wanted to. I still have time though.”

He could tell by the expression on the young Prime’s face he was at a loss for words. The expression was a mix of fear, confusion, and amazement. Optimus didn’t know what to make of it.

Sentinel smirked as he crossed his arms and leaned against the garage door frame.

**Notes for the Chapter:**

> I honestly didn't know how to go at this pairing because of size difference and how it work out between them so...yeah. I'm not right, am I?


	2. Serenity

Optimus hit the fake protoform model, moving back and forth, side to side to get a better angle. 

Lately, the young Prime had made everyone concerned for one day he was the usual, the next and to now, he was cranky and downright angry at the world. Using test dummies as his personal punching bags was odd enough but watching him swing every killing blow seemed to show a much darker side to Optimus that not many had ever seen before. Was he ill? Was he mad at someone specifically? All these questions, but no answers made one suspicious that something was being hidden from ally eyes.

Ratchet reluctantly told Sentinel to talk to Optimus and find out what’s been eating at their leader’s heels as of late. The elder Prime doubted his word would change anything, but if he couldn’t do it, what was the chance anyone else can?

Sentinel watched from a comfortable distance as several more strikes were severely brought down on the poor, ripped dummy who’s arm was nowhere to be seen and its head was barely hanging on by a single piece of metal that made up its skin. If it was sentient, it would have been dead by now.

“Optimus, what are you doing?” The fire truck sighed, raising his brow.

“Just trying…to keep myself…from tearing…Starscream’s head…off,” he panted as he performed a high kick that sent the dummy flying backwards into other equipment.

Shaking his head, Sentinel moved to Optimus’ side with concern, “Okay, what happened?”

“That seeker insulted you and the entire lineage of the Primes, not to mention attacked Sam, practically killed Bumblebee, and desecrated Jazz’s grave! So if you don’t mind, dear mentor, I would really like to be left alone. I’m perfectly fine!”

“Clearly,” the red and silver mech sarcastically replied. “I have a method to help you relax, to balance your emotions or cancel the negative ones by bringing positive ones out. If you’re willing to be patient and calm enough to do it that is. How about we treat it as a lesson, one to concentrate on self-control or perhaps anger management. You of all bots should know that anger only makes you sloppy in battle, and to fight Starscream in this way will get you either injured beyond repair or killed; the second outcome is definitely not an option.”

Optimus didn’t smile or show any emotion other than hate, “I know what you’re doing, Sentinel. That will not calm me no matter how persistent you are. Interface does not solve everything!”

“No but it heightens movements, it releases all bad emotions, it makes you forget the stupid remarks of a flying imbecile who can’t tell his own motherboard from a Dorito chip! We’ll get Starscream later. Patience is a warrior’s greatest weapon and still makes crime pay today, but only when those who take time to use it properly will it serve others well. Think, boy, what did I teach you? Either you fix your attitude now and start acting more Prime-like, or you can sit in your anger until you’re sick and tired of pushing everybody away with this idiotic emotion! And trust me, a lot of people are not happy on how you’re acting!”

No retort came from the semi. He just stood there, staring at his teacher. Finally, he said, “Very well then, I’ll take you up on your offer. But I’m not forgetting what Starscream did to Jazz’s resting place.”

“Fine, fine. Get over here so I can help you, you stubborn jackass!”

To the elder Prime’s surprise, a smile tugged at the corner of his student’s mouth but still kept distant. But, he snarled when Optimus suddenly pushed him to the ground and pinned his arms to the floor. Now his pupil was smirking tauntingly. “I said I’d interface with you. I never said I’d let you be the dominant one first. I believe both ways of interface are needed to put the fire burning within me.”

Sentinel growled as the young Prime began teasing him by rubbing his groin plating against his own. He hated being the receiver of interface more so than losing in battle. He despised knowing someone else was in control. Optimus knew this and probably was doing this on purpose as revenge for disturbing his workout. 

When the semi heard his mentor groan after moving over the closed area of the elder’s pressurized spike, he leaned down and roughly captured the fire truck’s lips with his own, increasing the friction between them. As he distracted Sentinel, he sent a signal to his interface array and felt more intoxicating heat flow through his body; his spike and valve grinded against the abdomen below him. He noted how Sentinel grew rigid when the other realized what he was doing.

Hearing the click of the old Prime’s interface open, he rose up to look at his partner exposed. Both spikes were aligned beside one another as were their valves. Repositioning himself to having one of his legs to go under Sentinel’s, Optimus pressed his lubricant-covered opening to the other, rolling his hips to begin the release he now desperately craved. 

Sentinel’s servos dug into the ground as he felt his arousal increase with each stunning thrust his successor provided. His vision began fading white as he watched both he and Optimus connect, transfluids coating their valves as they rocked into each other. He moaned as a burst of pleasure rushed to his processor, indicating his overload was building quickly. Warnings flashed rapidly as Optimus grew more impatient; he cried out as he was slammed into, arching as he was taken over the edge in bliss.

Optimus forced his opening as close to Sentinel’s valve as he could go, clutching the latter’s leg when the orgasm rippled within him like an earthquake. He called out his mentor’s name before panting and rocking a little more to make the beautiful overload last a bit longer. Lubricants pooled below them and when Optimus removed his valve from Sentinel, more leaked out.

The young Prime then grabbed Sentinel’s legs and wrapped them around his waist despite a hoarse protest from the other. “Optimus, you had your chance to be top! Let me take over from here!”

“Uh, no. You want to help me get rid of my stress and anger, you’re going to participate in what I want to do and how I desire to do it, old mech. You’ll get your turn when I see…and feel fit. Now, open wide,” Optimus purred.

Much to Sentinel’s dislike, he had no choice but to obey. He felt the tip of his student’s spike position near his entrance, barely breaching the wet folds before finally sliding in him. He winced slightly but whatever pain was apparent soon was replaced with pleasure. 

Slowly, Optimus began propelling his appendage at a constant speed into the fire truck’s ingress, kissing Sentinel once again. The moans the mech beneath him sounded made him move faster. He could feel the valve reacting greatly to his movements; the grip the valve had sent waves of wonderful feedback to his member. Before he knew it, he was pounding his mentor to oblivion, feeling his former negative emotions spill out through each thrust.

The valve then clamped down on his pulsing spike with enormous pressure, making him cum practically on cue. He got a few more good thrusts before he too overloaded. He grinned in triumph as he heard his name being screamed by his partner, feeling the lubricants overflow his teacher. After the orgasm died down, he collapsed on top of Sentinel exhausted, moaning as the red and silver mech bite his neck in response. 

“We aren’t done yet, boy. I still need to do my part in your journey to serenity,” Sentinel whispered.

Optimus didn’t say anything as he got off his mentor and opened his legs wide on all fours beside the mech. He felt the other mount him quickly before a surge of ecstasy rushed throughout his body fast like a bullet. He moaned as the inner nodes of his valve were suddenly hit with an amount of force he couldn’t describe. Occasionally, he bucked back several times to stimulate a stronger wave of pleasure.

The Rosenbauer Panther smirked as he witnessed his student arch and bow to accommodate his series of thrusts. “That’s it, give in. Control your emotions and direct yourself. Let the anger out.”

Growing intolerant, the semi moved backwards to get the entire member in him. When he felt it suddenly leave his valve, he cringed and quickly peered up at Sentinel lustfully. 

“Sentinel, please, finish me now!”

He growled when a servo wrapped around his throat and pulled him to be cheek to cheek with the fire truck. 

“Either you will be patient or I will stop and leave you wanting. Do you desire such a thing?” The red mech hissed.

“No! Please continue.”

Releasing his throat, Sentinel reentered the Autobot leader. Not stalling anymore, he slammed himself into Optimus once again. The heat became unbearable as both bots roared upward. 

Optimus took his mentor’s spike to the hilt, pressing into him desperately. He whimpered as his valve overflowed with their combined liquids. He nearly bit his glossa before his overload cooled as his fans worked overtime. When he felt Sentinel pull out, he smiled. “Thank you, old friend.”

“Feel better, my pupil? Good, ‘cause I ain’t doing no more. I’m done for the night.”

The semi chuckled, “My anger has ceased and I too should rest now. What would I do without you to keep me company? To teach me restraint when I need it most?”

“You’d probably be dead because of cockiness and stubbornness. You would’ve died in the first battle for Cybertron if I wasn’t there to teach you shit. I’d honestly hate to see what you could have become.”

Raised brows turned sarcastically mellow, “Thanks.”

Sentinel grinned, “The anger’s gone. See, what did I tell you? Interface solves these types of situations. And you thought I was an idiot?”

“I never said that; I just didn’t trust your judgement.”

The Rosenbauer Panther began laughing as he cleaned himself off.

**Notes for the Chapter:**

> So this happened. I warned you all! If you actually made it to the end and are reading this, kudos to you. If you didn't and/or skipped down here to leave behind the smut, that's cool too. This was originally for ErinPrimette.


End file.
